194 THE ATOMIC WEIGHTS. 



agreeing values for the atomic weight of titanium. The cross ratio, 

 4AgCl : Ti02 is not directly given by either of Thorpe's series ; but the 

 data furnished by Rose and Demoly combine into a general mean of 

 4AgCl : TiO, : : 100 : 13.980, ± .0303. 



Some two years later Thorpe published his work more in detail * and 

 added a set of determinations, like those made upon the chloride, in 

 which titanium tetrabromide was studied. Three ratios were measured, 

 as was the case with the chloride. In the first, the bromide was decom- 

 posed by water and titrated with a silver solution. 



0027 



In the four last experiments of the preceding series, the silver bromide 

 formed was weighed. The third column gives the TiBr^ proportional to 

 100 parts of AgBr. 



,0049 



For the third ratio the bromide was decomposed by water; and after 



evaporation with ammonia the residual titanic oxide was ignited and 



weighed : 



TiBr^. TiO.,. Per ce7it. TiO-^. 



6.969730 I. 518722 21.790 



8.836783 1.923609 21.768 



9.096309 1-979513 21.762 



Mean, 21.773, ± .0062 



lo-noring Mosander's work as unavailable, we have the following ratios 



to consider : 



(I.) 4Ag : TiCl^ : : 100 : 44.017, ± .0031 



(2.) 4AgCl : TiCl^ : : 100 : 33.123, =fc .0019 



(3.) 4AgCl : TiO, : : loo : 13.980, ± -0303 



(4.) TiCl^ : TiO.2 : : 100 : 42.171, d= .0022 



(5.) 4Ag : TiBr, : : 100 : 85.235, zh .0027 



(6.) 4AgBr : TiBr^ : : loO : 48.962, ± .0049 



(7.) TiBr^ : TiOj : : 100 : 21.773, ± .0062 



* Journ. Chem. Soc, Feb., 18S5, p. 108, and March, p. 129. 



